On 02/05/2016 08:02 PM, Dan K wrote:
Another great tip. This plagued me for a long time,
until
I realized that I had only one drive connected, and it had
the resistor network IC unpopulated. I borrowed it from
the other drive (they were on the same wire, so I suppose
that only one resistor network is necessary) and that's
what led to my initial success.
Yes, the terminating resistor pack should only be
in the
last drive on the cable.
It seems to do the job, but I still don't have a
replacement pad. That seems to be okay however, because on
one drive the head load solenoid doesn't appear to come
down far enough to push the disk very much. I don't think
I've ever seen the pad on either drive come down enough to
physically touch the disk--maybe just brushing it, barely.
What might cause this?
Probably wear, or maybe warpage of the parts over time. The
pressure pad should be fairly soft, usually a felt-like
material. It needs to push the media into contact with the
read-write head. Without it, you will occasionally get good
enough contact to read a sector header or even a whole
sector, but it won't be consistent. The data will come and
go as the disk rotates.
Jon